Seismic Performance Study Of Frame Structures Based On Deformation Of Components

Nowaday, the method of seismic design in our country is that, the checking calculationof bearing capacity as well as deformation under small quakes is usually carried out by usingelastic method. Further, seismic measures play a major role in reaching the goal of ’repairableunder moderate earthquake and no collapsing under strong quakes’. Actually, the seismiccollapse resistance of structures under rare quakes can hardly be precisely caculated. Eventhough the checking calculation of inelastic deformation under rare earthquakes is used bysome structures, but it appears to be some deficiencies to measure the structural or partialfailure roundly by story drift.This paper put forward the method for seismic performance based on deformation ofcomponents, which is stated on two aspects. Firstly, structural damage is measured by storydrift, so that the structures will not lose capability. Secondly, it is important to control thecapability of components drop in20percent, using the method of evaluating componentperformance based on deformation index. Thus, it is helpful of researchers to study seismiccollapse resistance of structures, learn about the actual damage state under strong quakes andverify the reasonability of seismic measure by adopting the method of seismic performanceaccess based on deformation of component. Moreover, it`s also of great practicability toengineering.This paper designs twenty-seven regular frame structures with different seismicintensities, different ground motion and different height. Besides, twenty required seismicwaves for each structure are selected. Then, use Perform-3D and the pre-post-processingprogram to carry out the elastic-plastic time-history analysis. According to seismicperformance access based on deformation of components, the researches for seismic collapseresistance of structures under strong quakes are completed. This paper mainly consists of thefollowing contents:(1) Estimate the safety performance of frame structures under rare earthquakes by themethod of seismic performance access based on deformation of components, and make a study for the relation of two aspects in this evaluation, story drift and performance ofcomponents. Additionally, it finds that, most regular frame structures in our codes meets therequirements of safety and have some safety stocks, just only the nine-story frame structureswith seismic grade two are collapsed.(2) Relating to the Incremental Dynamic Analysis (IDA), this paper takes the ratio ofsafety R as the index to measure the seismic collapse resistance of structures. In order to learnabout seismic performance of the frame structures, analyzing them with IDA from someaspects, including the structures’ failure mechanism, the relation of damage and story drift,the ratio of safety and so on. It recognizes there is no relation between the damage and storydrift. Based on the ration R, the building height and the seismic measures makes a great effecton the seismic collapse resistance of structures. Specially, it is the frame structures in ourcodes with seismic grade two that have poor performance to resist collapse.(3) According to the analysis, it finds some solution to improve the structure design. Thispaper strongly suggests that, the high-rise fame structures with seismic grade two must bedesign as the structures with seismic grade one.